Double-acting pressure fluid lift pump for oil wells



March 3, 1953 L. DAVIS 2,630,071

DOUBLE-ACTING PRESSURE FLUID LIFT PUMP FOR OIL WELLS Filed Oct. 18, 1950 3 Sheets-Sheet l L o U/J D a V/J INVENTOR.

Maw mm A TTORNE Y L. DAVIS March 3, 1953 DOUBLE-ACTING PRESSURE FLUID LIFT PUMP FOR OIL WELLS Filed Oct. 18, 1950 3 Sheets-Sheet 2 MM M V m mew omw m w\ 0m A C l B l 4 w Gk. 4 z 0% A f 5 no 7. 7 o F L A '9 w A 4 1 43 4 //;///=L//A k fig 1 gr 7 77/\/ \YQJ! mm w J //n Q! vM 4 9 l O a 2 IE f0 7 March 3, 1953 L. DAVIS 2,630,071

DOUBLE-ACTING PRESSURE FLUID LIFT PUMP FOR OIL WELLS Filed Oct. 18, 1950 3 Sheets-Sheet 5 Z ou/s DOV/J INVENTOR.

BY JMILL'BQM A TTORNEY Patented Mar. 3, 1953 noustntoi iivornrssust niacin PUMP FOR OIL WELLS Louis Davis, Corpus Christi, Tex -assignor of twenty-seven and one- "WJHarris, Bay City, T

half per cent to George 6X.

This dnven tion relates to a well: pump which is adapted to be lowered into the tubing string of acaised well pump; the loweringmeans beinga conventional wire line. Su'ch invention is an improvement over my 'refil'ed app1icatiorr=Seria1 -No. 17 ,467, filed- August 3, 1950, but differs therefrom in that-the well pump is double -acting;

It'is arr-object of thisinventibn-to providea well pump which is adaptedtobe lowered into the tubingstring-ofa cased well bore bya wire dine; such-pump being assembled with a packer and :slips so that-the packer may be set above the pump when 'in lower .p'ositionand so that the slips maybe set to retain the pump-in such-position. In --such' assembly the annulus between pumping assembly-and tubing string is-sealedoff when the-packer is set withthe result that the fluid :pressure below the packer operates to move fluid upwardly into the tubingwstring and into communication with the pump which transfers :it upwardly through the tubing- -stri-ngthereabove.

-It :is an objectdr this invention to provide a pump of this class whichacts' to transfer fluid both" on the-downstroke and up stroke of the .piston- It isa fiupther object of this invention toprovide a .pump of this class which-has a floating piston" operable ona valve stem between two resilient elements, one ofwhich is compressed near the end; of the up stroke-and the other near the end c-"f the down stroke to'bui-ld up axially acting. forces upon the valve stem to transfer' it etween seating positions.

This yet a further object of this invention to provide a pump of this lasswhich is adapted to maintain a continuous delivery of'liq'uid into the tuI-bingstring-l thereabove, thereby avoiding; slippage-of the fluid; as happens in conventional production methods whereby gas pressure is employed to transfer a liquid.

It is yet another lamest of thisifivention to :provide a pumpof this class which operates at the inherent pressure of the reservoir of fluid therebelow and therearcund and which does not require the .pressurizing. of the casing annulus by admitting gasthereint-o from the top of the well.

It is -still afu'rther object of this' invention to provide a: of: this class which is adapted 'to-b'elowered into a tubing. string, as Ioy 'a= wire line; thereby obviating theconventional method WhiCh requires the icweringof atomiste tubing string and pump assemblytopro'dueing level.

Other and turthei ob ects: will be. apparent when the specification 10h with the diawingsin which:

is considered iri conned"- Fig. 1 is an'elevati'rin of the assembled pumpirig 'unit inposition at the bottom of'th'e tubirfg string 'ina cased wenand in "which po'sitiomthe slips have not beenset.

Fig. 2' is a sectional elevation through the pumping unit shown inFig. lanainthiseleva =ti6n the "slips are "shown set in the tubing string and the packer-expanded to seal 01f the space therebelow.

'Fig. 3 'is-an enlarged sectional elevation of the upper portion of the pump shown working on the up stroke.

Fig.4 is an'enlar'g'ed sectional elevation of the central portion of the pump-shown working on the up stroke.

Fig: 5 is an enlarged sectional elevation of the lower portion of the pump-shown workin'gmn the up stroke. a A

Fig-i 6 is anenlarged-sectional elevation of the upper "portion'of the pump showing- -details'- of the valve stem locking means; valve head. and bumper construc-tiomsuch elevation being taken along lines 6-6*o-f*-Fig; 3. s V

, Fig. 7 is a sectional plan view taken along line 1=- 'lof--Fig.'3 I

Itwell known that in wells, as-oi1 wens, a producing formation may produce fluid under excessive subsurface pressures. If the pressure ofthis fluid can be converted into the force to lift it from the well, and this conversion can be accomplished through the medium ofapump lowered into, anchored in and'sealing off around the tubing string to isolate thespace therebelow adjacent" such: formation; then the necessity of employing a force actuated from the top oft-he well, as the injection of gas, may be obviated.

Gon'seque'ntly, this-inventions'ets out to accoin plish this purpose-and a preferred type of pump therefor, as disclosed in the drawing, will be hereinbelow described. 7

In Fig. 1 a pumping unit assembly I is shown when it has been lowered to approximately the bottom of a tubing or pumping string 2 ins, cased well; bore 3. Such a well bore has been perforated-asset 4' to permit communication between a'produeing formation 5 and the interior 6 of the well here. The tubing string 2 is closed by a perforated end member 1 through which perfoiations 8 the fluid may pass into communi= cation with the pumping unit-'11 eapumping unit c'o'nipfis stheipumphousing for such connection.

valve head 3? H], the mandrel head l2, the slips [3, and the spear head M, which is connected to the top of the slips. 'The packer and slips may be of conventional construction and any type of slip may be employed which can be set when the assembly is in desired position and which can be released when it is desired to withdraw the assembly. Also any type of packer may be employed which can be set when the assembly is at a desired elevation in the tubing string and which can be released by movement of the pumping unit in the thing string.

The pump housing has a top cap I 5 into which the mandrel i0 is threaded. Below the cap. in the pump i6, is positioned, as by threading, the seating element II which has the passage I8 therethrough and which has provided at its base the seat for a spring [9 which forces the ball against the valve seat 2|. Below the valve seat 2! is located the upper valve head 22 which has the lateral" ports 23 therein to communicate with the port rng 24 which is incorporated as part of the housing 9. The valve head 22 also has axially extending ports 25 therein wh ch communicate with the hous ng bore or interior 25 at the lower end of the valve head and which open at 2? into the bore 28 of the valve head near the upper end thereof.

The lower portion of the pump is of similar construction and has the bottom cap 29 connected to the lower valve head 39 which valve 'head has therearound the port rng 3| of the housing 9. The housing ports 32 in the port ring 3| communicate with the lateral ports 33 and the lower valve head 30. The axially extending ports 34 in the valve head 39 communicate at their upper ends with the housing interior 26 and at their low-er ends they open at 35, into the bore 35 of the valve head near the lower end thereof.

The valve stem 3'! extends from valve head bore 36 into valve head bore 28 and has the ends 39 and l!) which have thereon the vertically spaced apart lock ng rings 4! and 42. Bet een the ends 39 and 4!], and within the ho sing bore '25, the valve stem 3'! has fixed thereon the bumpers E3 and 44. Conventional means, as the set screw and the p n 46, may be employed The inner bumper ends are recessed at 4'! to receive the springs 48. piston 58, which has sealing rings 5| on its outer periphery to seal a ainst the valve stem 31, is slidable upon the valve stem.

In operation, the valve stem 31, seated as shown in F gs. 3-5, permits communicat on of fluid, as oil, throu h the housing ports 32 and lateral'ports 33 to the annular space'53 around the valve stem above the valve head 40. The l quid then passes upwardly and outwardly through the slots 54 in the bump-er 44 and fills the housing bore 26 and exerts a ressure on the lower surface of the piston to force the piston upwardly.

The piston moves 'pwardly until it contacts the spring 4-8 and begins compr ssing the string. During this t me the ax al ports 34 are blocked oiT from commun cation with the bore of the The groove 4! has the bal 55 seated therein, such ball being held thereaga nst by the spring 53 which is confined in the bore 58 and between the port ring inner wall 5'! and the outer ball surface.

As shown in Fig. 6 a imilar arrangement locks the valve stem end 39 by employment of the groove 4|. In this position the valve end 39 blocks off communication between the lateral ports 23 and the bore of the valve head 22. On the other hand, the axial ports 25 permit'communication between the housing bore 26 and the bore 28 thereabove.

The oil continues to fill the space below the piston and increases the pressure on the spring 48 until this pressure is sufficient to unseat the valve stem by forcing outwardly the balls 55 from the upper grooves 4!. The upper bumper end 60 is brought into contact with the lower surface Bl of the valve head 22 to stop further upward motion of the valve stem. The space between the bumper end 6?] and surface 6| is equal to the distance between the grooves 41 and 42 and at the point of contact of bumper end with the valve head the lower grooves 42 are contacted by the balls 55 to hold the valve stem in upper locked position. This change of position places the lateral ports 23 in communication with the annular "space 53 around the valve stem and within the valve head 22. The upper portion of the valve stem end 39. in such raised position, blocks off the axial ports 25.

At the same time the lateral ports 33 are closed, communication is opened between the axially extending ports 3-! and the bottom of the bore 36. This position of the valve stem is shown in Fig. 2. Fluid, as oil, now flows downwardly through the annular space 53 within the valve head 22 and enters the housing bore 23 to exert pressure on the upper surface 62 of the piston 50. The oil below the piston is thus forced downwardly as the piston descends and passes throu h the ports 34 into the bore 35 and upwardly through the valve bore 63 to lift the check ball 20 against the pressure of the spring Hi to permit the fluid to flow up the bore l8 and through t e mandrel l0 and on u wardly throu h the tubing string 2 to the top of the well. The p ston continues moving downwardly until it contacts the lower spring 48 and compresses it to finally unseat the valve stem 31 and move t to the position originally described and shown in Figs. 3-5.

In a pump of this class it should be noticed that there is a c ntinuous delivery of fluid upwardly into the tubing string so that the head of fluid is continuously increased until the whole tubing string is filled and delivery is being made at the top of the welle This is an efiicient and novel method of oil del very and compares more than favorably with the conventional method that requires a gas to be niected down theannular space around the tubing to intermittently force quantities of oil u wardly. This conventirnal method results in an a mixture of gas and oil in the tubing string and there is a loss of efiic encv due to downward sli pa e of the oil. The el mination of the requirement that gas-be injected from the top of the well is also a considerable saving.

It is broadly pointed out that in this invent on the pressures inherently occurring in the sealed off portions of the ell below the acker are sufiicient to op rate the ram In this regard it is pointed out that, of course, the annul s space bet een tubing str ng and easing must be closed at the t p n the well.

Th y facilit with which this tvpe of pumping assem ly can be positioned and removed is also 'a decided asset in o eration. It is onlv necessary to att ch a conventional ire l ne to t e spearhead H! to lower the assembly into position and t rem e it from the well.

Broadly, this invention considers a double acting pump adapted to be lowered into the tubing string of a Well; the packing element assembly with the pump being adapted to seal off the annulus between the assembly and the tubing string, and the slips of the assembly being adapted to anchor the assembly in pumping position. Also it is broadly pointed out that this invention considers a pump of this class adapted to operate by fluid pressures inherent in the sealed ofi portion of the well.

What is claimed is:

1. A double acting pump comprising, a housing having upper and lower port means therein, a

bored valve head in either end of said housing adjacent said housing port means, port means in each valve head for placing the adjacent housing port means and the bore of the valve head in communication, other port means in each valve head between the inner end thereof and the valve head bore outwardly of said first valve head port means, a hollow valve stem having ends operable in said valve head bores and having in succession inwardly from each end a bumper and a resilient member to seat thereon, a piston slidable on said stem between said resilient means, locking means on said valve heads and said stem ends adapted to retractably lock said stem to said valve heads in spaced apart positions, said upper valve stem end being adapted in lower locked position to close said upper valve head first port means while said lower valve stem end is adapted to close said lower valve head other port means, said upper valve stem being adapted in upper locked position to close said upper valve head other port means while said lower valve stem end is adapted to close said lower valve head first port means and to place said valve stem interior in communication with said lower valve head other port means.

2. In a pumping assembly adapted to be lowered by a wire line into the lower end of a tubing string in communication with fluid in the surrounding well bore, the combination of, a pump, packing means and slip means connected thereabove, when in desired position said packing means being adapted to seal the annulus between said assembly and said tubing string and said slips being extendable to grasp the wall of said tubing string to anchor said assembly, said pump including a housing having upper and lower port means therethrough and upper and lower valve means including a hollow valve stem operable therein and a piston slidable on said valve stem between said valve means, said valve means being adapted alternately to admit fluid through said lower port means and below said piston to force fluid above said piston through said upper valve means andto admit fluid through said upper port means to force said piston downwardly and to force fluid below said piston upwardly through said valve stem interior.

3. A double acting pump comprising, a housing having upper and lower port means therethrough and upper and lower valve means therein including a hollow valve stem operable in said valve means, a piston slidable on said valve stem, said valve means being adapted to operate alternately to admit fluid through said lower port means and below said piston to force said piston upwardly and fluid thereabove through said upper valve means, and to admit fluid through said upper port means above said piston to force said piston downwardly and fluid below said piston up through said valve stem interior.

4. A double acting, reciprocating pump for a well having a tubing therein and a pressure fluid in communication with the lower end of the tubing, said pump comprising, a housing having a tubular stem upstanding therein and reciprocably movable between two pre-determined positions, means to seal between said barrel and said tubing, a piston operable to slidably seal between said housing and said stem, a check valve in said housing above said piston, means in said housing to yieldably urge said piston axially of said stem, and valve means around said stem, said stem and said valve means being adapted to admit said pressure fluid into said housing to force said stem reciprocably between said positions and to urge said piston reciprocably upwardly and downwardly against said yieldably urging means, and to discharge fluid into said housing from said conduit and said valve means, and above said piston and said valve means.

LOUIS DAVIS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

